Receiver, System and Method for Frequency Diversity Communications Using Beacon and Methods Useful in Conjunction Therewith

1. A receiver-end apparatus for a communication system, comprising: a receiver add-on device operative to identify, within a received main signal, an auxiliary signal having predefined characteristics known by the receiver add-on device and a transmitter add-on device, and including a frequency diversity provider operative to use the auxiliary signal to identify, within the received main signal, a trigger commanding the frequency diversity provider to shift a center frequency of the received main signal; and a receive frequency converter subsystem added upstream of a receiver apparatus which uses a fixed center frequency, and wherein the receive frequency converter subsystem comprises: a synchronization detector, operative to detect predetermined portions of a relevant communication protocol signal according to a communication protocol, and a receive frequency converter module which performs a frequency conversion operation to reconvert back to an original center frequency including using a beacon signal for estimation and synchronization of at least one of time and frequency, wherein the receive frequency converter subsystem is operative in conjunction with a remote transmitter add-on device including a transmit frequency converter subsystem operative, when deployed downstream of a transmitter apparatus which uses the fixed center frequency, to communicate with the receiver add-on device to transmit the auxiliary signal to the receive frequency converter subsystem, wherein the transmit frequency converter subsystem comprises a second synchronization detector, operative to detect the portions of the relevant communication protocol signal in which frequency conversion/shift can be implemented, according to the communication protocol, and a transmit frequency converter that performs frequency conversion of an original center frequency, wherein upon detection of the portions, the second synchronization detector synchronizes the transmit frequency converter to perform a change of an alternative center frequency, wherein the auxiliary signal having predefined characteristics known by the receiver add-on device and the transmitter add-on device is used by the receive frequency converter module to coordinate the frequency conversion operation with the transmit frequency converter, and wherein the auxiliary signal having predefined characteristics comprises a continuous wave signal.

2. The receiver-end apparatus of claim 1 , wherein a receiving antenna is provided which covers all the shifted frequencies implemented by the transmit frequency converter subsystem and is interfaced to the receive frequency converter module.

3. The receiver-end apparatus of claim 1 , wherein the receive frequency converter module re-converts the shifted center frequency to the original center frequency.

4. A communication method, comprising: providing a receiver-end apparatus for a communication system, comprising: providing a receiver add-on device operative to identify, within a received main signal, an auxiliary signal having predefined characteristics known by the receiver add-on device and a transmitter add-on device, and including a frequency diversity provider operative to use the auxiliary signal to identify, within the received main signal, a trigger commanding the frequency diversity provider to shift a center frequency of the received main signal, the receiver add-on device comprising a receive frequency converter subsystem, added upstream of a receiver apparatus which uses a fixed center frequency, and wherein the receive frequency converter subsystem comprises: a synchronization detector, operative to detect predetermined portions of a relevant communication protocol signal according to a communication protocol, and a receive frequency converter module which performs a frequency conversion operation to reconvert back to an original center frequency including using a beacon signal for estimation and synchronization of at least one of time and frequency, wherein the receive frequency converter subsystem is operative in conjunction with a remote transmitter add-on device including a transmit frequency converter subsystem operative, when deployed downstream of a transmitter apparatus which uses the fixed center frequency, to communicate with the receiver add-on device to transmit the auxiliary signal to the receive frequency converter subsystem, wherein the transmit frequency converter subsystem comprises a second synchronization detector, operative to detect the portions of the relevant communication protocol signal in which frequency conversion/shift can be implemented, according to the communication protocol, and a transmit frequency converter module that performs frequency conversion of an original center frequency, wherein upon detection of the portions, the second synchronization detector synchronizes the transmit frequency converter module to perform a change of an alternative center frequency, wherein the auxiliary signal having predefined characteristics known by the receiver and a transmitter is used by the receive frequency converter module to coordinate the frequency conversion operation with the transmit frequency converter module, and wherein the auxiliary signal having predefined characteristics comprises a continuous wave signal.

5. A transmitter-end apparatus for a communication system operative in conjunction with at least one communication network node having a capacity for communicating with at least one additional communication network node at a given fixed center frequency and according to a communication protocol, the transmitter-end apparatus comprising: a transmitter add-on device including at least one external transmit frequency converter subsystem, external to and deployed downstream of the at least one communication network node, the converter shifting the transmitted signal of the at least one communication network network node from the given center frequency to a first alternative center frequency, wherein the first alternative center frequency being changed from time to time during the communication between the at least one communication network node and the at least one additional communication network node, and wherein the external frequency converter is operative to transmit a beacon signal at a second alternative center frequency, in addition to the transmission of the communication protocol at the first alternative center frequency, wherein the transmit frequency converter subsystem is operative to transmit the beacon signal to a remote receive frequency converter subsystem, and wherein the transmit frequency converter subsystem comprises a synchronization detector, operative to detect portions of a relevant communication protocol signal in which frequency conversion/shift can be implemented, according to the communication protocol, and a transmit frequency converter module that performs frequency conversion of an original center frequency, wherein upon detection of the portions, the synchronization detector synchronizes the transmit frequency converter subsystem to perform a change of an alternative center frequency, so as to allow the receive frequency converter subsystem, when added upstream of a receiver apparatus which uses a fixed center frequency, to perform a frequency conversion operation to reconvert back to an original center frequency including using the beacon signal for estimation and synchronization of at least one of time and frequency.

6. The transmitter-end apparatus of claim 5 , wherein the beacon signal is transmitted only during partial intervals of the transmission of the communication protocol.

7. The transmitter-end apparatus of claim 5 , wherein the beacon signal spans over only partial frequency bandwidth as the transmission of the communication protocol.

8. The transmitter-end apparatus of claim 5 , wherein the beacon signal is a modulated signal carrying information.

9. The transmitter-end apparatus of claim 5 , wherein the second alternative center frequency is changed from time to time during the communication between the at least one communication network node and the at least one additional communication network node.

10. The transmitter-end apparatus of claim 9 , wherein the first and second alternative center frequencies are taken from a predetermined list of frequencies.

11. The transmitter-end apparatus of claim 5 , wherein the beacon signal carries information comprising the first alternative center frequency.

12. The transmitter-end apparatus of claim 5 , wherein the transmit frequency converter subsystem is connected to a transmitting antenna that covers all shifted frequencies implemented by the transmit frequency converter module.

13. The transmitter-end apparatus of claim 12 , wherein a power amplifier is added between the transmit frequency converter subsystem and the transmitting antenna.

14. The communication method of claim 4 , wherein the beacon signal is transmitted only during partial intervals of the transmission of the communication protocol.

15. The communication method of claim 4 , wherein the beacon signal spans over only partial frequency bandwidth as the transmission of the communication protocol.

16. The communication method of claim 4 , wherein the beacon signal comprises a modulated signal carrying information.

17. The communication method of claim 4 , wherein the beacon signal is transmitted at a second alternative center frequency which is changed from time to time during the communication between the at least one communication network node and the at least one additional communication network node.

18. The communication method of claim 17 , wherein the second alternative center frequency is taken from a predetermined list of frequencies.

19. The communication method of claim 4 , wherein the transmit frequency converter subsystem is connected to a transmitting antenna that covers all shifted frequencies implemented by the transmit frequency converter module.